A 62-year-old man fell down a several meter high slope with a dump truck in a quarry in Arnsberg (Hochsauerlandkreis) and died.
The man suffered fatal injuries in the work accident on Monday morning, the police said.
Accordingly, the cause of the accident is still unclear.
The public prosecutor's office called in an expert.
Arnsberg - The Office for Occupational Safety and Health is also investigating.
dpa